BGA (Ball Grid Array) is an advanced type of integrated circuit packaging technology which is characterized in mounting at least one semiconductor chip on a front surface of a substrate and implanting an array of solder balls on a back surface of the substrate. The solder balls act as input/output (I/O) connections to electrically connect the chip to an external device such as printed circuit board (PCB). The BGA configuration advantageously allows relatively more solder balls or I/O connections to be accommodated on a unit area of the substrate in accordance with high integration of the chip.
Following the rapid advances in electronic technology, electronic devices are developed towards multiple functionality and high performance. To achieve high integration and miniaturization of a semiconductor package, a single-layer circuit board is improved to be a multi-layer circuit board with interlayer connections for mounting more active/passive components and circuits.
Passive components such as resistors, capacitors and inductors are usually incorporated in the semiconductor package to enhance or stabilize the electric performance of electronic devices. For example, the resistor is used to adjust the current, the capacitor is used to temporarily store the voltage, to provide a filtering function, or to reduce noise in circuitry, and the inductor can filter noises out.
Referring to FIG. 7, U.S. Pat. No. 6,108,212 discloses a semiconductor package having a substrate 21 incorporated with conductive pads 21 and electrodes 22, wherein an electrically resistive volume 23 is formed between a conductive pad 21 and an electrode 22, such that the substrate 20 is electrically connected to an external electronic device 25 via metallic bumps 24 mounted on the conductive pads 21, and a set of conductive pad 21, electrode 22 and electrically resistive volume 23 function as a passive component to improve electric performance of the semiconductor package. However, such an integral substrate has complex structure to be fabricated and thus is cost-ineffective in manufacture; moreover, the substrate needs to be re-designed if different property values such as resistance value and capacitance value are required, which would significantly increase the manufacturing and material costs.
In addition, electronic components and electronic circuits are packed in high density in the semiconductor package and thus produce a huge amount of heat. If the heat cannot be timely dissipated in an efficient way, the performance and lifetime of the semiconductor package would be damaged by overheat. Furthermore, the semiconductor package generally lacks a shielding mechanism and is easily interfered by external electromagnetic waves and noises.
Therefore, the problem to be solved herein is to provide a semiconductor package incorporated with sufficient electronic components such as active/passive components and semiconductor chips, which can improve the electric performance, effectively dissipate heat and provide shielding for the semiconductor package.